ABSTRACT
In the 20th century air pollution has often been seen as the dominant factor in controlling damage to cultural heritage. This view, and one reinforced by this conference is hardly an inappropriate. However it is also important to focus on the concerns that will face us in the 21st century, so it is the longer perspective that I wish to emphasise here. In ancient times architects realised that although buildings were designed with permanence in mind they also suffered damage (Brimblecombe 1992). By the 17th century they realised the types of threats that confronted their creations. English architects such as Sir Christopher Wren and Nicholas Hawksmoor believed time, smoke and weather to be the principal destructive factors. Nevertheless on long time scales the situation can be complex. Indeed, as Peter Foster, the Surveyor to the Fabric of Westminster Abbey wrote (Foster 1985): “to blame everything on acid rain, atomic waste, aerosols or whatever is the latest ‘Green’ view of the world, is surely ‘simplistic’… .” Materials not only confront physical effects, but many of these pressures change over centuries. In contemporary society are the pressures from a changing climate. However the endurance of monumental architecture is also under significant pressure from social and political changes.
